Process and product for gluing wood with starch or substances containing starch



:enocnss Ann rnonuorron. Gnome woonwr'ria srancn on sunsrnicns conrnrnmo Patented Jan. 13, .1931" UNITED ST T EUGEN ABRAMOWITSCH, OF HAJ IIZBURG, GERMANY STARCE It is known to use vegetable glue for the manufacture of adhesives which, however, for instance, in Germany are not employed in' the practice for the purpose of gluing wood.

In other countries where vegetable glue is.

purpose, such as in; theused for the said United States, it is not nearly used to such an extent as animal glue. The reason for the limited use may particularly be seen in the slight agglutinant efiiciency of the vegetable glue, and moreover in the unsuitable procedure of gluing (cold compressing for hours) and the injurious action of the caustic alkalies corroding and coloring the wood which are added for producing or increasing 7 the aggultinant efiiciency.

Animal glue fundamentally difiers from vegetable glue in its chemical composition.

- In the case of animal glue, such as for instanceanimal casein, animal albumen, leather-glue or bone-glue the agglutinant action of the proteins is .fully utilized, whereas the protein-content of the vegetable glue is too small to be of any value.

. Fundamental differences may also be seen inthe purposes for which the adhesives are intended to be used, whether in connection with wood or with paper. In the latter case a rather small adhesive action will be sufiicient, since in View of the rather loose cohesion of-the paper fibres a vegetable adhesive, such as for example farinaceous adhesive paste will have a greater consistency than the fibres of an ordinary paper.

According to the process of the present invention a vegetable glue is used for the first time in connection with wood by converting the glue into a substance with sufficient-adhesive action, without an addition of any caustic alkalies or acids as is customary. When using vegetableadhesive made, for instance, of flour paste, a mass is required that spreads easily. For this purpose a rendered impracticable.

advantages of the process accordin -1I1Ve1'1t10IllI1' view of with additional substances, methylene or'a netural salt, for example mag- I No Drawing. Application filed October 6,1927, seam... 2: 3 m in as ram... if4',.1m.

state, a'jelly isobtained which does notallow it to be easily spread on the surface in question-and the use of" According to the method of the present which is therefore invention a high concentration of the adhesive means made of starch to the wooden surface suitably prepared, either in a dry state or as a paste or elly'or in any other form of suspension" containing about 30% starch in an unconverted state.

a material containin starch, is obtained by applying unconverted wheat, "rye,

etc., are then subjected to heat and pressure at a temperature of about 90 adhesive having a high adhesive efliciency. Onlyafter the conversion has taken place the to this previous me ods are brought about. ",Merely due tothe said conversion the vegetable glue becomes fit for being used in connection with wood. The treatment of the starch at a temperature of about 60 (1., viz. at a temperature causin the mole- -cules of the various kinds of stare to be destroyed will not'be sufiicient to produce, in

conjunction with carbohydrates, an eflicient glue. A higher temperature of about 90 C. is required so as to enable a conversion of the starch into an adhesive adapted to be employed for gluingwood.

The process of the present invention is carried outby applying starch or starch-containing substancesto the surface of the wood at an indoor temperature about 18 0., either in a dry state or, if desired, as a-pasty mass, jelly, viscous fluid, mucilage or in any other, suspension and the like, if required, mixed such as triox'yperature of about 90 C. whereupon the two surfaces will--adhere tojone another in a very short time.

p C. and pressure of 2-8" atmospheres thereby causing a conversion of the substances into a powerful As c examples of my invention. 1. 8 es of potato-flour are mixed with kilos of water-to furnish amil solution. 50 gr. magnesium chloride are t en added thereto and the whole mixed with 500 gr. ltragacant-h and 2 liter water.

2. 4 kilosof rice-flour are mixed with 4 kilos of rye-flour and the mixture mixed with 17 kilos of cold water. I

3. 8 kilosof corn flour are mixed with 17 kilos of water, 50 gr. trioxymethylene and 500 gr. dextrine, at ordinary temperature.

Such mixtures are applied to the surface of 'the wood by means of any well-lmown spreading device. The veneers after being laid in contact with. each other are then ut under-acompressive device which is eated to about 90 Celsius and, uickl closed with a pressure of 2 to 8 atm. n a hesive substance is produced thereby and causes the two surfaces to become permanently joined together. a r Y What'"Iclaimis:- 1. process for gluing wood with an aqueous compositionstareh containing substances which consists in applying the starchcontaining substances in an unconverted state to the wooden surfaces to be glued together, and then converting the said sub ,6 stances into a powerful adhesive under pressure and heat at a'temperature of about 90 C. v

2. A process as claimed in claim 1, in which the aqueous composition starch-containing substances are used in admixture with trioxymethylene.

o 3. A process for wood which comprises applgingto t e surfaces of thewood to be joine an aqueous composition including unconverted starch, uniting the surfaces 0 and putting the joined surfaces under heat and pressure. 1 a

4. The process of gluing wood surfaces which comprises coating the surfaces to be joined with an aqueous composition includ- 5 ing starch and trioxymethylene uniting the surfacesto be joined and placing them under 7 heatand pressure. 5. The process as in claim 3 in which the pressure is about 2 to 8 atmospheres and the 3 temperature is about 90 .C.

6. The process as in claim 4 in which the pressure is about 2 to 8 atmospheres and the temperature is about 90 C.

7. An adhesive comprising the product of heating an aqueous composition including unconverted starch to a temperature of 90 C.

under a pressure of about 2 to 8 atmospheres.

8. An adhesive comprising the product of heating an aqueous composition including unconyerted starch and trioxymethylene to a temperature of about C. under a pressure of about 2 to 8 atmospheres. In testimonywhereof I afiix my signature.

at m EUGEN ABRAMOWITSCH. 

